In recent years, global warming due to an increase in carbon dioxide emissions has become a problem, and controlling CO2 emissions is an important issue also in the steel industry. In response to this, the operation with a low reduction agent ratio (abbreviated as low RAR, total amount of a reducing agent blown from a tuyere and coke charged from a top of a furnace per manufacture of a ton of pig iron) has been promoted strongly in the recent blast furnace operations. Since coke charged from a top of a furnace and pulverized coal blown from a tuyere are mainly used as a reducing agent in a blast furnace, and in order to achieve a low reduction agent ratio, and eventually, control carbon dioxide emissions, a measure to replace coke or the like with a reducing agent having a high hydrogen content ratio, such as LNG (Liquefied Natural Gas) and heavy oil, is effective. In PTL 1 described below, a lance from which a fuel is blown through a tuyere is configured by a triple tube, pulverized coal is blown from an inner tube of the triple tube lance, LNG is blown from a gap between the inner tube and an intermediate tube, oxygen is blown from a gap between the intermediate tube and an outer tube, and LNG is combusted on ahead, so that the temperature of the pulverized coal is increased, and the combustion efficiency of the pulverized coal is improved. In addition, in PTL 2 described below, oxygen is blown from a single tube lance arranged in a blast pipe (blowpipe) to the central part of high-temperature air flowing in the blast pipe, and the temperature of oxygen is increased to several hundred degrees C., and moreover, pulverized coal is blown from a lance arranged so as to penetrate a tuyere, and the pulverized coal is brought into contact with heat oxygen of several hundred degrees C., so that the temperature increase of the pulverized coal is improved, and the combustion efficiency of the pulverized coal is improved.